<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    .box {
      width: 200px;
      height: 200px;
      border: 3px solid #000;
      font-size: 30px;
      margin-top: 10px;
    }

    .pink {
      background-color: pink;
    }

    .big {
      width: 300px;
      height: 300px;
    }
  </style>
</head>

<body>

  <div id="app">
    <!-- v-bind:class="{类名1: 布尔值, 类名2: 布尔值, ...}" -->
    <div class="box" :class="{pink: isShow, big: isShow}">黑马程序员</div>
    <!-- v-bind:class="['类名1', '类名2', ...]" -->
    <div class="box" :class="classArr">黑马程序员</div>
  </div>
  <script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
  <script>
    const app = new Vue({
      el: '#app',
      data: {
        isShow: false,
        classArr: ['pink', 'big']
      }
    })
  </script>
</body>

</html>